1. Field of the Invention
The invention relates to an optical element apparatus of backlight module for the liquid crystal display, particularly to an optical element apparatus for two-dimensional controllable localized partition backlight module.
2. Description of the Prior Art
The backlight module is generally one of key components of a liquid crystal display, since the liquid crystal itself has no not luminance; thus the function of the backlight module can supply sufficient luminance and even distribution light source, in order to enable the liquid crystal display to show the image normally.
As for the conventional backlight technology specified in “A High Dynamic Range Display Using Low and High Resolution Modulators”, SID 2003 Conference Proceedings (2003), a low resolution backlight module is used to combine a high resolution LCD panel to obtain the effect of high dynamic range display, reduce the dark state of conventional LCD, and raise the contract ratio. But the combination of the module is very complicated; the practical use is not highly increased.
In the research literature of “High Dynamic Range Display System”, ACM SIGGRAPH 2004 Conference Proceedings, two practical examples for low resolution backlight module and related corresponding algorithms are proposed. A projector is used as the backlight source of the relative low resolution. Although the effect is very good, the required volume space is very large, thus it is not competitive for practical application. Since an active light emitting diode (LED) matrix is used as the backlight source of low resolution, the optical field of each LED can not form the mutual independent regional field. Each LED field covers all operation areas of high resolution LCD panel, increasing the complexity of a convolution operation in accordance with the proposed algorithm. And it will consume time and hardware resource for the treatment of real time image signal, thus it will be limited for the practical application in the industry.
In addition, in the literature of “Deriving LED Driving Signal for Area-Adaptive LED Backlight in High Dynamic Range LCD Displays”, SID 2007 Conference Proceedings (2007), two algorithms are proposed to simplify the complexity of the original algorithm, but the optical method is not proposed to improve the complexity of the algorithm.
Upon summarizing the above-mentioned description, as shown in FIG. 1, the conventional backlight module 10 composed of optical element 11, light field distribution pattern 12 and LCD panel 13, which will cause uneven and distribution light source.
Corresponding with the promotion of the manufacturing technology of liquid crystal display, only the backlight module with light weight, thin shape, low power consumption, high illumination, and low cost can meet the requirement of market. It will be the diligent direction and important subject to develop and design the new-type backlight module and manufacturing technology in the future.